Automatic gear-shifting mechanism



bustion engines.

l Patented June 3,A 1924 i UNITED STATI-:s

l 1,496,211; PATENT OFFICE.

ALBERT A. DENSMORE, or BOSTON, MASSACHUSETTS, AssIGNOR To ECLIPSEMACHINE COMPANY, vOE ELMIEA HEIGHTS, NEW YORK, A CORPORATION OF'NEWYORK.

'AUTOMATIC GEABPSTIIFTING MECHANISM.

Application filed Maron 14 1922. Serial No. 543,581..v

T o all whom t may concern.'

Be it known that I, ALBERTA. DENsMoRE, V citizen of the United Statesof'A America, and resident of Bostoinin the county of Sudolk 5 and Stateof Massachusetts, haveV invented new and useful Improvements inAutomatic Gear-Shifting Mechanism, of which the following is aspeciiication.

This invention concerns automatiq'gear` 1.0 shifting mechanism and 1nthe embodlment herein disclosed relates more particularly to thevapplication of such shifting mechanism,-

to engine starting devices such as aret'zom-i monly employed forstarting Internal .come

The usual practice atv the-,present -is to providev thelyvwheel O f the-engine with ,-cordingly to provide automatic 'gearshift ing mechanismapplicable fOr-fusain the starting of internal combustion engines, suchgear` teeth on its` peripheral surface,"1or to mount a special gearWheel upon th'e engine shaft, and to drive the wheel, when start-ing.

the engine, by' means of a pinion of 'small' diameter 4meshing with suchteeth and rotated by an auxiliaryelectric motor. The dr1v1ng of therelatively large iiy Wheel by the small pinion permits the use` of anelectric.' motor of lsmall size and comparatively low power`v for'starting the engine; the arrangement de'- scribed being lpermissible byreason ofthe fact that it is only necessaryto turn the .e n vfgine'shaft slowly for producing the 1n1t1al lcompression and iiringg';of' the lfuel charge inA starting. If however, when.;A the engine startsto run -underits ovvn powenandthe fly Wheel picks up speed?, the Vmotorpinion' -be allowed' to remain in mesh withA the fiy.

Wheel gear teeth,l such pinion, With'the-mof:

tor shaft and rotor .will be driven `at a 'speed far in excess of thatfor' which Vsuch parts are designed, causing heating of the bearings andrapid deterioration of the motor parts.

To avoid this difficulty it has been 'proposed to so arr'ange'thedriving pinion upon the motor shaft asto permit it to be 'moved into andout -of meshwith vthe fly Wheel gear at f the proper times, and' inorder; to relievethe large operator of'the engine of the necessity ofshiftingsuchfpinion intoand out of meshvg' 1 ing relation to the y`Wheel gear, certainv forms of automatic gear shiftmg'mechanismj haveheretofore been devised. In most such mechanism, relativelymovable`parts havin'g intermeshing screw threads are employed for determiningthe interconnection of lthe ticular for which "the mechanism is pri'marlly lntended. Moreovenas the operator is accustomed' to place entiredependence .upon this mechanism and as it, together with' 'the motor'are commonly concealed from view, any failure of'such\mechanism to dis-Wheel with lthe motor shaft, andwhile 'such devices in most cases areeffective for 55 connect the `motor 'at the proper time may l tion. I

The object of the present invention. is acliable 'in Operation undef allconditions of'usef YVhile the inventive idea herein disclosed may'obviously be expressed. in various 'con remain unnoticed untilthe-lmotor has suff' feredfsnbstantial injury or complete destruccreteVforms, a single physical'v embodiment i of meanswell adapted Afor usein. attaining the 'desired result is herein illustrated, by Way lofvexample, in the accompanying drawings in Which:-

- Fig. 1 'is a longitudinal,- vertical cross section through themechanism of the invention herein disclosed, showing certain associatedparts in elevation, and illustrating the position of 'the operativeparts ofthe mechanism when the engine is running;

Fig.` 2 is afrontelevation, partly in cross section', of' the devices'shown in Fig, 1, but

illustrating the parts in lthe' position which eine;

scale on' the line a-b of Fig. 1;- Fig. 4 is asimilar cross section 'onthe line c-dofFig. 2;l

gV 3 ".isa transverse' cross section to ,they` occupy during thestarting ofthe en# Fig. 5. is a cross 'section to large scale'onReferring. to the drawings, an internal iu disclosed.

combustion engine of any known type is indicated generiilly at 1, suchengine having a fly wheel 2 provided with a spur gear 3. rl`his Arearmay comprise teeth formed in` legi-ally with the rim of the. ily wheelor may consist of a separate gear secured thereto, or il desired suchAgear might be attached to the engine shaft independently of the ilywheel. At tis indicated an electric motor ol' the type commonly employedin connection with internal combustion engines for starting the latter,such motor receivinel its` energy from a suitable source. such forexample. as a storage battery, not here- The motor L1 is provided with ashaft :3. which for convenience, and as herein illustrated. may be ofsquare or other polygonal cross section at its end portion, as indicatedat G. Mounted upon the polygonal portion of the shaft', for rotationtherewith, is a yoke 7 having at its closed end a sleeve. portion Sprovided with an opening of suitable form for the reception of the endof the shaft. The parts may be secured to- `other by means of a pin 9passing through the sleeve and shaft. 'V'Vhile as herein shown the shaftis squared at its end, it is to he understood 'hat the invention is notconcerned particularly with this arrangement, but that any suitablemeans may be employed for securing the yoke to the shaft to rotatetherewith.

The yoke preferably comprises a pair of` face 2() of such block engagesthe rollers 17,"

18, andupon rotation of the sleeve u12 in the properdirection the block19 is rotated therewith, the parts being so constructed and arranged,however, that movement-off the block 19 at a speed greater than that'ofthe sleeve- 12 serves to disconnect Suchparts. Although a roller clutchis especiallydesirable for the purpose, by reason 'of itsnoisef lessnessand certainty in actiomit is evident that other types of unidirectional,or;.ratchet,A clutch may be as good or better,under some conditions ofuse, than-the clutch'h'er'e disclosed. The block 19 .is preferablyprovided with a circumferential groove 21 with which engages the innerend of apin 21a secured in thesleeve 12, the block 19 being thusprevented from 'moving axially-With respect to the yoke, While at thesame time relative rotation' of such parts is permitted.

The block 19 is provided with an axial bore through which passes alshaft 22, the shaft beingA free for axial movement as well as rotationwithin the block. The shaft. projects beyond the block and into thespace between the yoke arms 10, 11, and at its end is threaded at. 23for the reception of a` nut 24. This nut serves to secure a collar 25.upon the shaft, and interposed between said collar and the end of theblock 19 is a coiled compression spring' 26 surrounding the shaft. vWiththe parts thus arranged the sprinpr 2G normally tends to move the shaft22 toward the left with respect to block 19 as viewed' such sleevebeiner free to rotate and also to slide axiallyl of the shaft. Mountedupon one end of this sleeve is a pinion 31 which may he caused to meshwith the gear 3 upon proper movement of the sleeve in a longitudinaldirection. While this pinion may be fixed directly to the sleeve, it ispreferred to arrange it for limited movement. both in an axial andcircumferential direction relathe sleeve. `If desired the ends of theteethV of thevpinion`31 or of the vgear3, or of both may be suitablybevelled, undercut or other- Wise shaped to facilitate the properintermeshing of the pinion teeth with those of the gear as the. pinionis moved vtoward the latter." The other end of the sleeve 30 is ofrelatively large diameter` as indicated at 32, and Within the chamberformed between the Walls of-.such enlarged portion and the shaft v22, acylindrical block 33 isl arranged, this block having an axial openingfor the. paserably secured to the sleeve member 32. so as to partake ofthe axial movement of the latter, by means of a pin 36 engagingT acirsage of the shaft 22. The block 33 is prefcumferentialgrooveB in theblock 33. The

.block 33 is vfixedly. secured to the shaft'22 by meansof a pin 37. Theend of the block 19 is 'provided with a cam surface 38 whichiscomplemental to a cam surface 39 formed upon the adjacent end of theblock 33. f

y In theedge of the enlarged portion 32 .of

the sleeve 30, a recess is provided, such recess having an end wall 41lying in a plane substantially perpendicular to the axis ofr 'hile asherein disclosed, both blocks 19 and 33 are provided with inclined camfaces, this may not always be necessary,v as a cam element `upon one ofsuc-h blocks only might under certain circumstances, be sufficient forthe purpose. Moreover, while a certain type of cam is hereinillustrated, it is to be understood that any mechanical element havingequivalent functions might be substituted for the device herein shown ifcircumstances should so demand. In a modified form of the device shownin Fig. 6, the cam block 19a is provided with an oblique andsubstantially plain cam face 50, while the cam block 33 is provided witha complemental and substantially plain surface 51.

It being assumed that Athe parts occupy the position of Fig.v 1 theoperation of the device in starting the 4engine is as follows: Uponclosing of a suitable switch to energize the motor 4, the shaft 5 isrotated, thereby rotating the yoke 7 and the sleeve 12. The rotation ofthe latter serves to pick up the rollers 17, 18 thereby clutching theblock 19 to the yoke and causing such block to rotate with the motorshaft 5. Immediately upon rotation of the block 19, the cam face 38thereof, reacting against the cam face 39' of the block 33 pushes thelatter block axially toward the engine. As the shaft 22 is pinned to theblock 33. such shaft also moves with the block thereby placing spring 26under compression. At the same time the sleeve 30 is caused to movelongitudinally with the block and the shaft until the pinion 31. iscarried into mesh with lthe gear 3". If upon initiation of movementofthe pinion 31 toward the gear 3, the teeth of the latter should beopposed tothose of the gear, the pressure upon the end face. of thepinion would cause it to move axially along the sleeve. compressingspring 30e. Such movement however, immediately results in rotating thepinionby reason 'of engagement of pin 31b with the cam slot 30a. Thismovement of the pinion serves to bring the teeth ofthe' latter oppositethe spaces between the teeth of the gear 3, whereupon the spring .30acts to snap the pinion quickly into mesh. The. length and angularity ofcam slot 30a need only be suicient to produce a rotary movement of thepinion of substantially one tooth width. This action takes place duringthe first half rotation or less of the motor shaft. proach each other,the lug 43 enters the recess 4() bearing against the end wall 41 thereofand also against the side wall 42. The

engagement of the lug with the end wall 41 i serves in a positive mannertemporarily to prevent the 'spring .2 6 from; restoring the shaft 22andthe sleeve to normal position, while the engagement ofthe lug withthe As the high parts of the cams ap-j shoulder 42 Serves to transmitmovement of rotation from the rotating block 19 to the sleeve 30,thereby positively rotating the pinion 31 and the gear3. The pinion 31continues to rotate in this manner until the engine shaft has beenturned over sufficiently to provide the 'necessary compression andignition of the charge. When the engine picks up speed under its ownpower, the gear 3 serves to drive the pinion 3l 'at a rate faster thanis imparted thereto by the motor 4. As soon as this 'takes place, therecessed portionof the sleeve member 32 is advanced beyond the lug 43and at the same timeF the cam members 38 and 39 are moved relatively insuchfashion as t'o permit the spring 26 Vto retract the shaft 22. Thisserves to draw the pinion out of engagement with the gear 3 and thegreater the difference between 'the speed of the engine shaft and thatof the motor shaft the more certain is this disengagement to take place.It is thus clear that there is no possibility, so long as the partsremain intact, that the motor shaft will be driven for any length o ftime from the engine shaft.

If during the operation of withdrawal of the pinion31 from the gear 3,undue cohesion of the engaging parts as by the aecumulation of grease ordirt thereon, should besuch as to delay such withdrawal for any extendedperiod, thel provision of the roller clutch, comprising the members 12,19 and the rollers 17, 18, serves to avoid any substantial speeding upof the motor shaft, as immediately upon an increase of speed of themember 19 with respect to the member 12, such parts become unclutched sothat no power is transmitted from the part 19 to the part 12.

Thus by the use of two independent devices, the moto-r 1s insuredagainst overspeeding by connection with the engine shaft scribed withrespect. tothe device of Fig. 1.

While a desirable arrangen'ient has herein been specltically described,it 1s to be understood that various changes in detail struc'-.comprising a. longitudinally slidable. nonrr`ota ry support, a rotarydrive pinion mounted thereon. Aspring means constantly urging saidsupport in one direction` means for moving said support in opposition tosaid spring and carrying the pinion into engagement with a member of theengine to be started, and means for rotating said pinion.

2. AutomaticI gear shifting mechanism comprising a longitiulinallyYslidable, nonrotary guide shaft. a rotary pinion thereon, means normallyurging said shaft in one direction, means for moving said shaft in the'opposite direction and carrying the pinion into engagement with a memberof the engine to be started, and means for rotating said pinion.

3. In combination with a driven gear, a driving pinion. a. non-rotaryguide shaft for supporting said pinion to slide into and out of meshwith said gear, means normally tending to move said pinion out of meshwith the gear, and cam means for moving said pinion into mesh with thegear.

4. In combination with a driven gear, a pinion, a non-rotary guide.shaft for-movement into and out of mesh With the driven gear, springmeans normally operative to move said pinion out of mesh with the. gear,means for moving said pinion in opposition to the spring, and meansautomatically operative after the completion of such latter movement forrotating the pinion.

5. A mechanism of the class described con'iprising a slidable shaft,means for preventing rotation of the shaft, resilient means urging saidshaft in one direction, a rotary cam element for moving the shaft inopposition to the spring, a pinion freely rotatable upon the. shaft andcarried by said.

cam action upon the shaft into engagement with a member of the engine tobe started, and means for rotating the pinion.

6. A gear shifting mechanism of the class described comprising anaxially movable shaft, means to prevent rotation thereof, a member fixedto the shaft, a member mounted for rot-ation about the, axis oftheshaft, one of said members having afcam element engageable with theother, a pinion axially movable VWith the shaft but free for rotationthereon, and means fordotating'the movable,

member and the pinion. A

7. A gear mechanism for transmitting motion from a -motor shaft Yto anengine shaft gear comprising an axially movable the motor shaft forimparting movement to said movable sha-ftwhereby first to carry thepinion in to mesh with the gear and then. to rotate said pinion.

8. An automatic gear shifting mechanism comprising a pinion, an axiallymovable, rotary member forsupporting the pinion, a non-rotary shaftonwvhich said pinion and rotary member are mounted, said member having asubstantially radial abutment, al rotary cam for moving said supportingmember in an axial direc-tion, and a lug moving With said cam andengageable with said abutment for rotating said supporting member andpinion. v i

9. A gear shifting mechanism comprising anaxially movable shaft, meansto prevent rotation thereof, an abutment member fixed to the shaft, amember mounted for rotation upon said shaft and having an inclined camface engageable. With the abutment whereby I to impart longitudinalmovement to the prising an axially`movable, rotary sleevev having apinion mounted thereon, said sleeve having a recess in its inner Wall,means for moving said sleeve in an axial direction, and means rotatingabout the axis of the sleeve and engageable with said recess forpositively rotating said sleeve.

11. A device of the' class described comprising an axially movable androtary sleeve provided at one end with a portion of relatively largediameter, a pinion connected to the other end of -the sleev`e,'a blockcoaxial with the sleeve and disposed Within the larger end thereof.rotary cam means engageable with said block for moving the sleeveaxially, and a lug moving with the cam means and engageable with vanelement of the sleeve for positively rotating the latter. i

12. A mechanism of the class described comprising an axially movable,rotary sleeve having a part of large diameter at one end,

said. part having a `recess in itsedge, a blockseated withinA said largeportion of the sleeve and rotarywith respect thereto, a second rotarycam block. ,coaxial with the sleeve, said 'latter block having-acam facecooperable with an element kof thefirst block to impart axial movementto the latter and to thev sleeve, a driving member adapted to engage a'member of. the engine to be started and responsive to the movements ofsaidsecond block, and a lug projecting radially from the second blockand engageable with 'the recess to impart movement of rotation to thesleeve.

13. A device of the class described com prising `an axially movable,non-rotary shaft,

a lpinion mounted for rotation thereon and for axial movement with theshaft, an abutment member-secured to the shaft,'said member having a camface, a second member arranged adjacent to the abutment member upon'theshaft, said second member being vfree to rotate and having a cam faceengageable with thecam face ofthe abutment mem'- ber, and means forrotating said second member and for rotating the pinion.

1.4. .A 4 gear mechanism Vfor transmitting movement from a motor to afly wheel gear comprising a n'on-rotaryshaft aligned with the motorshaft, andmovable `inan axial .direction, a pinion mounted for freerotation upon the axially movable shaft, means constraining the vpinionto move axially with l* the shaft, a block fast to theshaft, said blockhaving acam face vat one end', a member mounted for rotation upon saidaxially mov# able shaft and having an element engageable'with said camface, means movable upon rotation of the motor shaft for rotating saidrotarymember, and means for imparting .movement of rotation tothepinion.

15. An engine starter device comprising anj axiallyv movable, non-rotaryshaft, a -pinion,mounted on-'the shaft-'for axial Inove-k.'ment..therewith, a block mounted upon th lshaft for .free rotationthereon, a collar fast .-to the shaft, a' coil 'spring encircling theshaft and interposed vbetween'the-.collar and' the 4block, a' secondblock fast to-the shaft and for axial movement with; the shaft, ya camelement upon one of vsaid blocks and engage-1 ahlewith the other, andmeans forvrotating 1 6. An engine/starter, device 4comprising incombination with a motor shaft a yoke having means for securing it to amotor` shaft, a block carried by the yokeand-hav- `ing a centralopening, an axially movable, non-rotary shaftpassing freely` through' aomeansnormally urging .said shaft in one direction, and interengagmg .camelements,

said-opening, a. pinion mounted-on the' shaft for axial movementtherewith, spring one .of which is carried by said block, for

imparting .longitudinal movement to the non-rotary shaft upon rotationof the motor shaft. I l

17. -An engine starter'V device comprising in combination with. amotorshaft an axially movable, nonrotary shaft, af pinion mounted on theShaft foraxial movement therewith, a cylindrical' block rfix-ed to theshaft and-provided with a cam face at one end,"a secondl block mountedfor `free ro# tation relatively to theshaft and having a cam face at oneend complementary toand engageable with the aforesaid cam face,and'means for'connecting said second block to a motor shaft for rotationthereby. Y

18. Anengine starter 'comprising in combination with a motor shaft ayoke, means for securing said yoke to the motor shaft, a block carriedby the yoke, said block having an axialopening and-an obliquel end face,a non-rotary and axially-movable'shaft passing freely through saidopening, a pinion mounted on the shaft vfor axial movement collar andtheblock, anda second block ixedtothe shaft andhaving an oblique .end

face engaging the end fa'ce of the first block.

' 19. A mechanism .ofthe class described4 comprising in combinationvwith a motor therewith, a-.collar upon the shaft and with` inthe yoke,a spring interposed betweenthe shafta yoke member p rovided with'means..

whereby it may be secured toa motor shaft,

a sleeve fast to said yoke member and constituting the driving elementof. a roller clutch, a cylindrical b lock arranged within said sleeveand constituting the driven ele- -ment of said clutch, clutch .rollsinterposed between said-elements, a second and .axially movable blockcoaxial with said first block and having a cam facev engageabletherewith, va pinion movable axially with said second' block, andv.means for transmittin movement of rotation from said `first bloc ."tosa-id pinion.v 'l 20. A' device'of' the class described com-v f'prisingA anon-rotary, longitudinally mov# able, elongate support,apinion` mounted for rotation upon said support,ablock having 'an'inclined end facefixed to said support, -a second and rotaryblockmounted upon said support adjacent to said first the other direction,and the pinion. v l

21.- A starting device. for usev with internal combustion enginescomprising a pinion engageable withagear on the .engine 'I shaft, anaxially n10-treble, rot-ary sleeve supporting the pin-ion, aezrmmembermou'nted" hfor rotation relatively to the sleeve, but movableaxially there-With, abutment means ea-rried b'y the sleeve, an axiallymovable,`

non-rotary shaft vpassing' freely through. the sleeve,means'xlnggsavldcam member theretor* a second and 'comp-lementnl. cam

spring surrounding the shaft and interposed between rthe collar `:tudsaid 4second cam member, an element movable with said seeoml CamV memberand engageuble with the aforesaid abutment, means for rotatngsad secondcanrmernber, and means for preventing axial movement thereof.l v

Signed byme at Boston,- Massachusetts,

ths 8th dayof March, 1922.

A ALBERT A. DENSMOKE,4

